refactor: add devMessage field (useful in front-end)

src/app.ts

@@ -20,6 +20,14 @@ const APP_PORT = +(process.env.APP_PORT || 3000);
 
   RegisterRoutes(app);
 
+  app.get("*", (_, res) =>
+    res.status(404).send({
+      status: 404,
+      message: "Route not found.",
+      devMessage: "unknown_url",
+    }),
+  );
+
   app.use(error);
 
   app.listen(APP_PORT, APP_HOST, () => console.log(`Listening on: http://localhost:${APP_PORT}`));